The difference between application/x-www-form-urlencoded and Multipart/form-data

When learning <form> elements, the enctype attribute has three values

Enctype attribute table:

value /th>
application/x-www-form-urlencoded	Encode all characters before sending (default)
multipart/form-data
text/plain	spaces are converted to "+" plus signs, but no special characters are encoded.

Where the,<input> element's type attribute must be file when the value is Multipart/form-data.

Type attribute table:

value	Description
button	Define clickable buttons (in most cases, use JavaScript to launch scripts).
CheckBox	Define the check box.
File	Define input fields and "Browse" buttons for file uploads.
Hidden	Defines the hidden input field.
Image	Defines the submit button in the form of an image.
Password	Defines the password field. The characters in the field are masked.
Radio	Defines a radio button.
Reset	Defines the reset button. The reset button clears all the data from the form.
Submit	Define the Submit button. The Submit button sends the form data to the server.
Text	Defines an input field for a single line in which the user can enter text. The default width is 20 characters.

Later, when I was learning the requests module, I came into contact with application/x-www-form-urlencoded and Multipart/form-data, and said the following:

The enctype represents the MIME encoding.

application/x-www-form-urlencoded: The form data is encoded as a name/value pair. This is the standard encoding format.

Multipart/form-data: The form data is encoded as a message, and each control on the page corresponds to a part of the message.

Text/plain: Form data is encoded in plain text with no control or formatting characters.

Add

The Enctype property of a form is encoded in two common ways: application/x-www-form-urlencoded and Multipart/form-data, which are application/by default. X-www-form-urlencoded.

When action is get, the browser uses x-www-form-urlencoded encoding to convert the form data into a string (Name1=value1&name2=value2 ... ), and then append the string to the URL, using the. Split, to load the new URL.

When the action is post, the browser encapsulates the form data into the HTTP body and then sends it to the server.

If you don't have a type=file control, you can use the default application/x-www-form-urlencoded.

But if you have type=file, you will need to use Multipart/form-data. The browser splits the entire form into units of control and adds content-disposition (form-data or file), Content-type (default = Text/plain), name (control name), and so on for each section. and add the separator (boundary).

Summarize

The message body is tagged, which is the MIME type. With this tag, the browser and server will be able to know the type of the data and then use the appropriate way to process the data.

MIME type structure

The difference between application/x-www-form-urlencoded and Multipart/form-data